The invention is generally related to the field of automatic telephone dialing and more particularly to computerized systems and methods system and method for facilitating determination by a calling device as to whether a called device connected to a telephone line is a fax device, non-fax data device or voice telephone, or combination thereof.
Scan-dialing of telephone numbers can be important in a number of environments for a number of purposes. For example, an organization may wish to determine, for each of the telephone numbers which it controls, the type or types of equipment, if any, that are connected to the telephone numbers which are associated with the lines. Numerous types of equipment may be connected to a telephone line, such as a voice telephone, an automatic voice answering system (such as an answering machine or a voice mail system), a fax machine, a data modem, and the like. In addition, several types of equipment may be connected to a single telephone line; for example, one line may be shared between a fax machine and a data modem through a switch that directs a call to one or the other based on information, such as tones or tone sequences, that are received from the caller. An organization may wish scan-dial and automatically detect types of equipment connected to telephone numbers which it maintains, for example, instead of trying to inventory the equipment manually, since equipment can be easily connected, disconnected and reconnected to other lines, which would render the inventory out of date. In addition, an organization may wish to scan-dial telephone numbers which it maintains in order to determine whether any of the telephone lines accessible using the respective are connected to equipment which is not authorized by the company or which is not secure pursuant to company policy. In addition, for computers which are connected to the telephone lines which an organization maintains, the organization may wish to ensure that passwords which may be required to access the computers through their dial-up connections are not such as would be easily guessed by an intruder.
U.S. patent appn. Ser. No. 09/216,101, filed Dec. 19, 1998, in the names of Simson L. Garfinkel, et al., and entitled xe2x80x9cSystem And Method For Scan-Dialing Telephone Numbers And Classifying Equipment Connected To Telephone Lines Associated Therewithxe2x80x9d (hereinafter, the Garfinkel application) describes a system and method for scan-dialing telephone numbers and classifying equipment connected to telephone lines associated therewith as being connected to one or more of a plurality of types of equipment, including, for example, a telephone set for voice communications, a fax machine or a fax modem for transmitting and/or receiving digital data defining facsimile images, and/or a data modem for transmitting and/or receiving other forms of digital data. It will be appreciated that a telephone line can be classified in a plurality of these classifications. For example, a telephone line can be connected to a modem that can function both to transmit and receive digital data defining facsimile images as well as other types of digital data. In the following, digital data defining facsimile images will be generally referred to as xe2x80x9cfax data,xe2x80x9d whereas other types of digital data will generally be referred to as xe2x80x9cdata.xe2x80x9d
An xe2x80x9cadaptive answeringxe2x80x9d technique is often used by a modem connected to a computer or other device that receives a call to determine which of a plurality of types of calls it is to enable it to transfer the dat to a fax program or a non-fax data communication program. That is, a modem will use an adaptive answering technique to determine whether a received call is a fax call, in which the data to be transmitted during the call is fax data to be handled by a fax program, or a data call, in which the data to be transmitted is non-fax data to be handled by a non-fax data communications program. Typically, when a fax machine or modem initiates a fax call, after it dials the call it will immediately begin transmitting a characteristic tone, and the answering modem can determine whether a call is a fax call if, when it answers the call, it receives the tone, and thereafter provide the received data to the fax program. On the other hand, if the answering modem does not receive the tone, it can determine that the call is a non-fax data call and transfer received data to the data communications program, and, in addition, transfer data that it might receive from the communications program to the other device over the same telephone line.
Adaptive answering provides for effective call discrimination by a called device as between a fax call and a non-fax data call. However, a scan dialing system such as that described in the Garfinkel application, as a calling device, needs to be able to determine whether the called device is a fax device, non-fax data device or voice telephone, or combination thereof, in connection with an adaptive dialing, or call origination, methodology.
The invention provides a new and improved system and method for facilitating determination by a calling device as to whether a called device connected to a telephone line is a fax device, non-fax data device or voice telephone, or combination thereof.
In brief summary, in accordance with one aspect of the invention, the invention provides an adaptive dialing method in which a dialer control module controls a modem to place a telephone call to a telephone line and efficiently classify the telephone line, that is, to determine whether a device connected to the telephone line is one or more of a plurality of types of devices, illustratively, a voice telephone, a fax machine or modem, or a data modem. In accordance with the method, the dialer control module can enable the modem to, in one call, determine whether the telephone line is connected to a voice telephone, on the one hand, or a fax machine or modem or a data modem, on the other hand. During the same call if the dialer control module does not determine that the telephone line is connected to a voice telephone, or during a subsequent call if the dialer control module determines that the telephone line is connected to a voice telephone, the dialer control module determines whether the telephone line is also connected to one of a fax machine or modem, on the one hand, or a data modem, on the other hand by enabling the modem to transmit an appropriate tone thereto and determining whether a connection is completed in response. The dialer control module can repeated the last operation using the appropriate tone to determine whether the telephone line is also connected to the other of a fax machine or modem, on the one hand, or a data modem, on the other hand